Self-adjusting bit and holder



April 24, 1951 F. K. BROWN ET AL SELF-ADJUSTING BIT AND HOLDER Original Filed July 9, 1948 Patented Apr. 24, 1951 SELF-ADJUSTING BIT AND HOLDER Frank K. Brown and Harvey F. Phipard, Jr., South Dartmouth, and George E. Jenney, Jr., North Dartmouth, Mass., assignors to Research Engineering & Manufacturing, Inc., New Bedford, Mass.

'Gontinuation of application Serial No. 37,848,

July 9, 1948.

1950, Serial No. 143,424

8 Claims.

Our present invention is a novel and improved holder to provide for self-adjusting transmission of power from a driving element to a driven element at divergent angles, and is a continuation of our prior application Ser. No. 37,848, filed July 9, 1948, and allowed September .22, 1949, now forfeited.

The invention, in preferred form, is utilized with either a hand-operated or power-actuated driving element and a detachable and replaceable bit, thus allowing different bits or tools for different sized articles or fasteners to be driven thereby, and preferably the self-adjusting or self-aligning holder is attached to the shank or upper part of the driver and, in turn, is detachably secured to the bit or tool which constitutes the lower part of the driver for direct engagement with the fastener or other article being driven. I

Primarily the invention is intended for screwdriving work, and more particularly for use with a bit or tool which will cooperate with a recessed or socket head fastener such as the well known different types of socket head screws, wherein it is desirable to have the bit fit the recess in the screw with sufficient accuracy to retain the screw on the bit and united thereto when applying the same to the work. Thus the driving torque will efliciently and effectively drive the fastener in a predetermined line even though i the driving element is disaligned, our self-adjusting holder being, in effect, a self-aligning or universal joint connection.

A further novel feature consists in our novel and improved process of forming the driven element, which is preferably made from stock of cruciform shape, which is particularly advantageous in making the bit to fit the wedging type of recess or socket head in screws or other fasteners which relay upon a wedging action by alternate ribs or grooves or flutes in the end of the bit which is inserted in the recess of the fastener.

By thus making the stock of the bit in cruciform shape, it not only facilitates the formation of the tapering driving end as above noted, but also enables us to fit the upper part of the cruciform shape in a squared hole in our selfadjusting holder; thus insuring a strong, firm, and rigid rotative transmission of power or torque from the upper part of the driver thru our selfadjusting holder to the bit and which, furthermore, enables quick attachment and detachment of the bit in a squared end opening of the holder while still permitting a self-adjusting angular This application February 10,

2 alignment between the bit itself and the holder. Such holder may be a part of, or rigidly attached to the driving element or may have an additionally self-adjustment connection between the holder and the upper part of the driving ele-' ment. Thus, the angular self-adjustment for alignment or disalignment between driving and driven elements may be at the bit-connecting parts, or at a plurality of positions, preferably one at the connection of the bit and holder, and one between the holder and stem or shank of the driver.

In order to retain the removable cruciform bit in the square hole of the holder, we provide yielding retaining means which will interlock with the bit but enable it to be readily Withdrawn, said retaining means consisting in a ball fitting from the outer side of a groove in the holder and adapted to engage a notch of corresponding radius to that of the ball, which notch.

is formed in one or all of the ribs of the bit, and with an encircling spring bearing on the outside of the ball and around the holder.

A spring tension is thus secured while the rotative driving tension is effected by the interlocking of the cruciform ribs in the corners of the square holes. As it is desirable at present to have a plurality of four or more such bits to fit the varying sizes of standard types of recessed fasteners, it will be appreciated that it is most important to have a construction which allows quick attachment and detachment of the bit and holder. 7

' Our novel cruciform interlocking self-aligning or disaligning construction may also be utilized with other types of bits, wedging or straight screwdrivers, or similar tools for such purposes, particularly where quick attachment and detachment is desired, combined with great strength in driving torque to the bit, thru a driving and a driven element, and we wish to claim this feature broadly.

Referring to the drawings illustrating preferred embodiments of our invention:

Fig. 1 is a diagrammatic view illustrating our improved self-adjusting holder with the driving shank and bit at divergent angles;

Fig. 2"- is a longitudinal cross-sectional view of our holder uniting the driving shank and bit;

Fig. 3 is a cross-sectional view on the line 33 As shown in the drawings, a shank l is a part of a power-rotating driving element or as a portion of the handle for a hand-operated driver. If the element l is round, as is customary, the lower portion is squared as indicated at 2, Figs. 2 and 4, to fit in the central squared hole 3 of our holder 5, said squared portion 2 being bored to receive a bolt I, which bolt, in turn, fits thru corresponding diametrically opposite openings H and H2 in the holder 5.

The squared portion 2 of the element I is of sufiiciently less area than that of the squared opening 3 in our holder so as. to permit a slight rotative action of the element l on the bolt H] as a pivot, thus allowing an independentseLE-aligning feature in this construction in addition to that provided between the holder and the bit, as will be described.

Preferably, we form the holder with a pair of outer grooves I5 near theupper part of the holder and in position so that a circular spring lsifitting in the groove l5 will engage the ends of thebolt l and, thus, retain the same in position, while permitting ready assembly, removal, or replacement.

' A similar peripheral groove 29 in the lower outer surface of our holder is provided to permit a circular spring 2| to be housed therein, this spring being for the purpose of retaining a locking ball 25 fitting in an opening 25. formed thru one wall of the holder in. partial alignment with the groove 20, this opening 2% on its inner edge being of less diameter than that of the hall 2.5, as indicated at 28, to allow the ball to project slightly intov the squared. opening 3' the inside of our holder.

The bit, preferably of cruciform shape in .crosssection, is indicated at 39 with a plurality of flutes or ribs 3 l3 I, each rib having in the upper portion to interlock with the ball- 2'5 a notch 33, said ribs 31 being of appropriate diameter to ex tend into the corner portions of the square central opening 3.

The lower portion of the bit 30 is coined or otherwise formed, as indicated at 35, to fit wedgingly into a correspondingly formed and tapered recess in the head of the fastener 40.

As here shown, the coined engaging end 35. is of a standard contour to fit well known types of recessed head fasteners and wedgingly engage the same to hold the fastener on the appropriately tapered and formed point of the bit 36 so that they will be united to facilitate applying the fastener to the Work. Any suitably coined end or contour for the bit 3!} can be utilized.

Thus it will be seen that we have devised a connecting holder between the driving element I and bit or driven element 30, which, in turn, drives the fastener lil, affording a self-seating, self-aligning, universal joint action to permit the driving element l and the resultant driven element, or elements, to be at divergent angles. In the type of wedging bit and fastener typified by that herein illustrated, it is most important tohave the. bit 39 in correct alignment with the recess in the head 40 of the fastener. This is essential to insure a proper wedging action and consequent driving torque.

Referring to the form illustrated in Fig; 5, the self-adjusting aligningv and disaligning construction shows the holder portion 55 as apart of or rigid with the driving element or stem 5|, and is otherwise identical in outside and inside construction, as the holder 5. previously described, except that only the lower groove "and retaining;

ring are employed as indicated. The holder 50 and stem 5! may be welded or otherwise rigidly secured together, preferably by a wedging fit and a retaining pin.

The driving element in both forms of Figs. 1 to 4 or of Fig. 5 is equally efiicient whether in direct axial alignment with the bit and fastener or at a divergent angle therewith, and the self-seating orself-adjusting action within any reasonable limits which would be desired is readily afforded by the pivotal and yielding connection between our holder and the bit. The cruciform contour of the bit 3E where it enters the holder insures the driving torque from the corner portions of the squared opening 3; and the action of the ball 25 yieldingly held by the spring 2!, forcing the ball into one of the notches 33 in the cruciform ribs, permits quick attachment and detachment of different bits, while insuring a strong and firm rotative driving transmission of power to the bit from the holder.

We claim:

1. A self-adjusting driving connection of the kind described, comprising two elements united by a holder, said holder having a squared central recess with one element pivoted therein, and the cooperating element of cruciform cross-section constructed and arranged to fit cornerwise-in said squared opening.

2. A self-adjusting driving connection of the kind described, comprisingtwo elements united by a holder, said holder having a squared central recess with one element pivotally secured therein, and the cooperating element of cruciform shape in cross-section formed with recesses in the corners of said cruciform element, and yieldingly secured in said holder by impositive lockin means.

3. A self-adjusting driving connection of the kind described, comprising two elements united by a surrounding holder, said holder having a squared central recess-With one element pivotally secured therein, and the cooperating element ofv angular contour in cross-section, with its angles interlocking with the corners of said squared recess and being detachably secured within said surrounding holder by a yielding locking ball.

4. A self-adjusting driving connection of the kind described, comprising two elements united by a surrounding holder, said holder having a squared central recess and a peripheral groove, an opening from said groove into the interior of said squared recess, the cooperating element of cruciform shape in cross-section being provided with recesses in the corners of the cruciform elementdetachably secured by a yielding locking ball fitted in said opening and engaging a recess in the cruciform corners and held yieldingly in position by an encircling spring housed in said groove.

5. A self-adjusting driving connection of the kind described, comprising a driving element and a driven element, said driving connection consisting of a squared recess in one element and a cooperating member in the other element of cruciform cross-section constructed and arranged to fit loosely cornerwise in said squared recess, providing operative connection when said elements are in alignment or disalignment, in combination with yielding means engaging a rib of. said cruciform driver member to hold the driving and driven elements against longitudinal displacement.

6. A self-adjusting rotative driving connection of the kind described, comprising a driver and a bit, the driving connection consisting of a squared recess in the driver, and a cooperating element a driven element, said driving connection consisting of a squared recess in one element and a cooperating member in the other element of cruciform cross-section constructed and arranged to loosely interlock with said squared recess, whereby driving torque in alignment and in disalignment is effected from one element to the other.

8. A self-adjusting driving connection of the kind described, comprising a driver and a bit, the driving connection consisting of a squared opening in the driver, and a cooperating element of cruciform cross-section in the bit constructed and arranged to fit cornerwise in said squared opening, the cruciform ribs of the bit being of less Width than the walls of the squared opening in the driver, whereby driving torque in alignment and in disalignment is effected from one element to the other, in combination with impositive locking means uniting said driver and bit in loosely interlocked relation.

FRANK K. BROWN. HARVEY F. PHIPARD, JR. GEORGE E. JENNEY, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,759,101 Daniels May 20, 1930 2,254,486 Kaufman Sept. 2, 1941 2,317,319 West Apr. 20, 1943 2,392,039 Gideon Jan. 1, 1946 

